Stop me if you've seen this one in print before, but Dame Judi Dench once told a colleague of mine that she wanted to punch me on the nose over something I once said in print. I offer this as a prelude to yet another breathless rave about our finest, unshowy actress. In Notes on a Scandal, the Richard Eyre-directed, Patrick Marber-scripted adaptation of Zoe Heller's novel, Dench gives a performance remarkable for its unloveliness. Her character, Barbara, is dumpy, spiteful, selfish and deluded. When she fixates on Cate Blanchett's younger teacher Sheba, and uses Sheba's affair with a pupil to crowbar her way into her life, it's clear that this is not a whim but a piece of repeat behaviour. Barbara is a destroyer, but whether she became wicked because she is lonely, or became lonely because she is wicked, is a moot point. Dench doesn't judge or justify, she merely reveals. I don't think she's ever been given the chance to be so brilliantly unsympathetic on film (unless it was by accepting a role in The Chronicles of Riddick, and she even came out of that with dignity).

By the way, on the subject of dames, Eileen Atkins once told me that there is an annual dinner for every Dame of the British Empire except the theatrical ones (Atkins, Dench, Plowright, Rigg, Mirren, Smith, sure there's one I've forgotten) who are excluded on the grounds of being, well, theatrical. Anyone know if it's true?

Back to Dench: we seem to be in a halcyon period, if that doesn't sound too much like a name for a retirement home, of top notch roles for older actors, in whose company Helen Mirren looks like a slip of a girl. Apart from Dench's Barbara and Peter O'Toole's gallantly undignified Maurice in Venus, I've just seen Albert Finney's cameo in Michael Apted's Amazing Grace. Out in March, this is is the tale of William Wilberforce's long fight to end the slave trade. Wilberforce himself is played by clean-cut Ioan Gruffudd, that well-known small Welsh town, but Finney is all sputum and stubble as the man who inspired the reformer: an ex-slaver who found God and who wrote the titular hymn, but who goes to bed every night with 20,000 screaming souls clawing at his conscience.

I won't say much more about Amazing Grace, except that it's a terrible title for a deeply honourable film, and it's written by Steven Knight, who also wrote Dirty Pretty Things, and who clearly sees film as a moral force. As he is also the co-devisor of Who Wants To Be a Millionaire, maybe this is his own form of atonement.

One last point about Notes on Scandal. Zoe Heller has been complaining mildly about minor liberties taken with her novel. When I spoke to Ian McEwan about Roger Michell's film of Enduring Love, he lamented the brutalising effect cinematic adaptations had on his fiction. Now, these writers' feelings are understandable, and I know they are almost certainly being prodded into these responses by hacks like me, but I do think it is a bit rich to take the money and then get snippy. They could at least be witty about it. When Pat Barker was asked how she felt about selling her tale of northern English working-class matriarchal strength, Union Street, to Hollywood (where it was made into the sickly Stanley and Iris, starring those well known proles Robert de Niro and Jane Fonda) she replied: "It's a bit like leaving your 15-year-old daughter on Jack Nicholson's doorstep. You know no good will come of it." Far wittier than any joky links I could have come up with...